The energy regulator Callum McCarthy held an emergency meeting with Enron's administrators late on Thursday night amid fears that the collapse of the energy trading giant might cause blackouts across the UK.

The meeting followed a telephone call from Mr McCarthy, the chief executive of Ofgem, to the administrators at PricewaterhouseCoopers during which he warned that ministers might have to be contacted unless Enron's position in the market was clarified.

However, spokesmen for Ofgem, National Grid and Elexon, the company which oversees the balancing and settlement system for electricity trading, all denied that the UK was in danger of being blacked out.

Ofgem said: "We were very keen to talk to the administrators primarily to ensure they understood Enron's obligations and responsibilities under its licence and the balancing and settlement code. But there was absolutely no risk of a loss of electricity supply on Thursday and the market is operating normally today."

National Grid said the electricity market was "short but not hugely short" on Thursday night and that the system had reacted as it was designed to with the Grid buying power to cover shortages as contracts were left unfilled.

Elexon said two Enron energy trading companies had defaulted on its balancing and settlement code.